LED module and method of manufacturing the same

ABSTRACT

A compact LED module and a method of manufacturing such an LED module are provided. The LED module includes a first-pole first lead, a first-pole second lead, a first-pole third lead, a second-pole first lead, a second-pole second lead, a second-pole third lead, a first LED chip, a second LED chip, a third LED chip, and a housing. A distal end of the first-pole first lead is offset toward a second-pole side in a first direction with respect to both a distal end of the second-pole second lead and a distal end of the second-pole third lead.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an LED module, and a method ofmanufacturing LED modules.

2. Description of the Related Art

An example of conventional LED modules is disclosed in FIG. 6 of JP2011-176264 A. The LED module disclosed therein includes three primaryleads arranged on the right side and three cooperating or secondaryleads arranged on the left side. The conventional LED module alsoincludes three LED chips mounted on the three primary leads,respectively, and these LED chips are connected via wires to the threesecondary leads, respectively.

In the conventional LED module, the primary leads are spaced from thecorresponding secondary leads by the same distance in the X-direction,so that there is a gap of the same width formed between each one of theprimary leads and the corresponding one of the secondary leads (threegaps in total). As shown in the figure, the three gaps of the same widthare elongated in the Y-direction and aligned straight in theY-direction.

The conventional leads with the above arrangements can be formed from ametal plate by a relatively simple process including presswork such asstamping. However, the mount locations of the three LED chips and thebonding positions of the wires may unduly be limited in variation, whichis not suitable to produce a compact LED module.

SUMMARY OF THE INVENTION

The present invention has been proposed under the foregoingcircumstances. It is therefore an object of the present invention toprovide an LED module that can be formed in a smaller size, and also toprovide a manufacturing method of such an LED module.

According to a first aspect of the present invention, there is providedan LED module including: a first-pole first lead, a first-pole secondlead, and a first-pole third lead located on a first-pole side in afirst direction; a second-pole first lead, a second-pole second lead,and a second-pole third lead located on a second-pole side opposite thefirst-pole side in the first direction; a first LED chip electricallyconnected to the first-pole first lead and the second-pole first lead; asecond LED chip electrically connected to the first-pole second lead andthe second-pole second lead; a third LED chip electrically connected tothe first-pole third lead and the second-pole third lead; a housingcovering at least a part of each of the first-pole first lead, thefirst-pole second lead, the first-pole third lead, the second-pole firstlead, the second-pole second lead and the second-pole third lead. Adistal end of the first-pole first lead and a distal end of thesecond-pole first lead are opposed to each other in the first direction,a distal end of the first-pole second lead and a distal end of thesecond-pole second lead are opposed to each other in the firstdirection, and a distal end of the first-pole third lead and a distalend of the second-pole third lead are opposed to each other in the firstdirection. The first-pole first lead is located between the first-polesecond lead and the first-pole third lead in a second directionorthogonal to the first direction, and the second-pole first lead islocated between the second-pole second lead and the second-pole thirdlead in the second direction. The first LED chip is mounted on thefirst-pole first lead, the second LED chip is mounted on the second-polesecond lead, and the third LED chip is mounted on the second-pole thirdlead. The distal end of the first-pole first lead is offset toward thesecond-pole side in the first direction with respect to the distal endof the second-pole second lead and the distal end of the second-polethird lead.

According to a second aspect of the present invention, there is provideda method of manufacturing an LED module. The method includes the stepsof: preparing a metal plate that is formed with an opening and includesa first-pole first bulging portion projecting into the opening from afirst-pole side toward a second-pole side opposite the first-pole sidein a first direction, the metal plate also including a second-polesecond bulging portion and a second-pole third bulging portion flankingthe first-pole first bulging portion in a second direction orthogonal tothe first direction, each of the second-pole second bulging portion andthe second-pole third bulging portion being configured to project intothe opening from the second-pole side toward the first-pole side in thefirst direction; stretching the first-pole first bulging portion in thefirst direction toward the second-pole side; stretching the second-polesecond bulging portion and the second-pole third bulging portion in thefirst direction toward the first-pole side; and mounting a first LEDchip, a second LED chip and a third LED chip on the first-pole firstbulging portion, the second-pole second bulging portion and thesecond-pole third bulging portion, respectively.

Other features and advantages of the present invention will become moreapparent through detailed description given hereunder with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an LED module according to a first embodimentof the present invention;

FIG. 2 is a bottom view of the LED module shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along a line III-III in FIG. 1;

FIG. 4 is a cross-sectional view of the LED module shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along a line V-V in FIG. 1;

FIG. 6 is a cross-sectional view taken along a line VI-VI in FIG. 1;

FIG. 7 is a plan view for explaining a manufacturing method of the LEDmodule shown in FIG. 1;

FIG. 8 is a plan view for explaining the manufacturing method of the LEDmodule shown in FIG. 1;

FIG. 9 is a cross-sectional view taken along a line IX-IX in FIG. 8;

FIG. 10 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1;

FIG. 11 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1;

FIG. 12 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1;

FIG. 13 is a cross-sectional view taken along a line XIII-XIII in FIG.12;

FIG. 14 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1;

FIG. 15 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1;

FIG. 16 is a plan view for explaining the manufacturing method of theLED module shown in FIG. 1; and

FIG. 17 is a plan view of an LED module according to a second embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described belowwith reference to the drawings.

FIGS. 1 to 6 illustrate an LED module according to a first embodiment ofthe present invention. The LED module A1 according to this embodimentincludes six leads, that is, a first-pole first lead 1A, a second-polefirst lead 2A, a first-pole second lead 1B, a second-pole second lead2B, a first-pole third lead 1C, and a second-pole third lead 2C. In theillustrated example, the three “first-pole” leads 1A-1C are arranged onthe right side of the module, while the three “second-pole” leads 2A-2Care arranged on the left side of the module. Further, the LED module A1includes a first LED chip 3A, a second LED chip 3B, a third LED chip 3C,a first Zener diode 4A, a second Zener diode 4B, a third Zener diode 4C,wires 51 to 58, a housing 6, and an encapsulating resin 7. In FIG. 1,the encapsulating resin 7 is not shown for the sake of simplicity. Inthe figures, the x1-direction corresponds to the “first-pole side in thefirst direction” in the present invention, and an x2-directioncorresponds to the “second-pole side in the first direction” in thepresent invention. The y-direction, orthogonal to the x-direction,corresponds to the “second direction” in the present invention, and thez-direction is orthogonal to both the x1-x2-direction and they-direction.

The first-pole first lead 1A, the second-pole first lead 2A, thefirst-pole second lead 1B, the second-pole second lead 2B, thefirst-pole third lead 1C and the second-pole third lead 2C serve tosupport the first LED chip 3A, the second LED chip 3B, and the third LEDchip 3C and/or constitute current paths to cause the LED chips to emitlight. The leads mentioned above are formed of, for example, Cu or Ni oran alloy of these metals.

The first-pole first lead 1A is located on the x1-direction side, and ata generally central position in the y-direction. The first-pole firstlead 1A has a strip-like shape extending in the x1-x2-direction, andincludes a thin portion 11A, a thick portion 12A, a distal end 13A, aterminal portion 14A, a narrowed portion 16A, a widened portion 17A, anda pair of grooves 18A.

The thin portion 11A, having a relatively small thickness compared withthe other portions of the lead 1A, is located on the x2-direction sidein the first-pole first lead 1A. The thick portion 12A, having a greaterthickness than the thin portion 11A, is located on the x1-direction sidein the first-pole first lead 1A. The boundary between the thin portion11A and the thick portion 12A (broken line in FIG. 1) is parallel to they-direction. As shown in FIG. 3, the respective upper faces of the thinportion 11A and the thick portion 12A are flush with each other. Thelower face of the thin portion 11A is covered with the housing 6 so asnot to be exposed to the outside, while the lower face of the thickportion 12A is exposed from the housing 6.

The distal end 13A, located at the farthest position on the x2-directionside in the first-pole first lead 1A, is formed as an edge parallel tothe y-direction. The terminal portion 14A is a portion via which the LEDmodule A1 is mounted on e.g. a circuit board, and provided by theportion of the thick portion 12A exposed from the housing 6.

The narrowed portion 16A has a relatively small width (i.e., smallerwidth than the adjacent portions flanking the portion 16A in thex1-x2-direction) in the y-direction. The widened portion 17A has arelatively great width (i.e., greater width than the adjacent portionsflanking the portion 17A in the x1-x2-direction) in the y-direction. Thewidened portion 17A is located on the x1-direction side from thenarrowed portion 16A. Having the relatively small width, the narrowedportion 16A has recessed ends in the y-direction. The widened portion17A, on the other hand, protrudes in the y-direction (more precisely, inthe opposite senses of the y-direction).

The grooves 18A are formed to cross the first-pole first lead 1A, eachextending in the y-direction from one edge to the other edge of the lead1A. The grooves 18A are located between the distal end 13A and thenarrowed portion 16A. In the illustrated example, the grooves 18A have atriangular cross-section as shown in FIG. 4, but the grooves 18A may beformed with a different cross-sectional shape.

In this embodiment, the distal end 13A, the narrowed portion 16A, thewidened portion 17A, and the pair of grooves 18A are located at the thinportion 11A.

The second-pole first lead 2A is located on the x2-direction side withrespect to the first-pole first lead 1A, and at a generally centralposition in the y-direction. The second-pole first lead 2A has astrip-like shape extending in the x1-x2-direction, and includes a thinportion 21A, a thick portion 22A, a distal end 23A, a terminal portion24A, and a bulging portion 25A.

The thin portion 21A, having a relatively small thickness compared withthe other portions of the lead 2A, is located on the x1-direction sidein the second-pole first lead 2A. The thick portion 22A, having agreater thickness than the thin portion 21A, is located on thex2-direction side in the second-pole first lead 2A. The boundary betweenthe thin portion 21A and the thick portion 22A (broken line in FIG. 1)is parallel to the y-direction. As shown in FIG. 3, the respective upperfaces of the thin portion 21A and the thick portion 22A are flush witheach other. The lower face of the thin portion 21A is covered with thehousing 6, and the lower face of the thick portion 22A is exposed fromthe housing 6.

The distal end 23A, located at the farthest position on the x1-directionside in the second-pole first lead 2A, is formed as an edge parallel tothe y-direction. The distal end 23A is opposed to the distal end 13A ofthe first-pole first lead 1A in the x1-x2-direction, with a gaptherebetween. The terminal portion 24A is a portion via which the LEDmodule A1 is mounted on a circuit board for example, and provided by theportion of the thick portion 22A exposed from the housing 6.

The bulging portion 25A is located on the x1-direction side of the lead,and protrudes downward in the y-direction in FIG. 1, i.e., toward thesecond-pole third lead 2C.

In this embodiment, the distal end 23A and the bulging portion 25A arelocated at the thin portion 21A.

The first-pole second lead 1B is located on the x1-direction side, andon the upper side of the first-pole first lead 1A in the y-direction asshown in FIG. 1. The first-pole second lead 1B has a strip-like shapeextending in the x1-x2-direction, and includes a thin portion 11B, athick portion 12B, a distal end 13B, a terminal portion 14B, a bulgingportion 15B and a groove 18B.

The thin portion 11B, having a relatively small thickness compared withthe other portions of the lead 1B, is located on the x2-direction sidein the first-pole second lead 1B. The thick portion 12B, having agreater thickness than the thin portion 11B, is located on thex1-direction side in the first-pole second lead 1B. The boundary betweenthe thin portion 11B and the thick portion 12B (broken line in FIG. 1)is parallel to the y-direction. As shown in FIG. 5, the respective upperfaces of the thin portion 11B and the thick portion 12B are flush witheach other. The lower face of the thin portion 11B is covered with thehousing 6, and the lower face of the thick portion 12B is exposed fromthe housing 6.

The distal end 13B, located at the farthest position on the x2-directionside in the first-pole second lead 1B, is formed as an edge parallel tothe y-direction. The terminal portion 14B is a portion via which the LEDmodule A1 is mounted on a circuit board for example, and provided by theportion of the thick portion 12B exposed from the housing 6.

The bulging portion 15B is located on the x2-direction side, andprotrudes downward in the y-direction in FIG. 1, i.e., toward thefirst-pole first lead 1A.

The groove 18B is formed throughout the first-pole second lead 1B in they-direction. The groove 18B is located on the x1-direction side from thedistal end 13B and the bulging portion 15B. The groove 18B may have across-sectional shape like the one mentioned above with respect to thegroove 18A.

In this embodiment, the distal end 13B, the bulging portion 15B, and thegroove 18B are located at the thin portion 11B.

The second-pole second lead 2B is located on the x2-direction side withrespect to the first-pole second lead 1B and, as shown in FIG. 1, on theupper side of the second-pole first lead 2A in the y-direction. Thesecond-pole second lead 2B has a strip-like shape extending in thex1-x2-direction, and includes a thin portion 21B, a thick portion 22B, adistal end 23B, a terminal portion 24B, and a groove 28B.

The thin portion 21B, having a relatively small thickness compared withthe other portions of the lead 2B, is located on the x1-direction sidein the second-pole second lead 2B. The thick portion 22B, having agreater thickness than the thin portion 21B, is located on thex2-direction side in the second-pole second lead 2B. The boundarybetween the thin portion 21B and the thick portion 22B (broken line inFIG. 1) is parallel to the y-direction. As shown in FIG. 5, therespective upper faces of the thin portion 21B and the thick portion 22Bare flush with each other. The lower face of the thin portion 21B iscovered with the housing 6, and the lower face of the thick portion 22Bis exposed from the housing 6.

The distal end 23B, located at the farthest position on the x1-directionside in the second-pole second lead 2B, is formed as an edge parallel tothe y-direction. The distal end 23B is opposed to the distal end 13B ofthe first-pole second lead 1B in the x1-x2-direction, with a gaptherebetween. The terminal portion 24B is a portion via which the LEDmodule A1 is mounted on a circuit board for example, and provided by theportion of the thick portion 22B exposed from the housing 6.

The groove 28B is formed throughout the second-pole second lead 2B inthe y-direction. The groove 28B may have a cross-sectional shape likethe one mentioned above with respect to the groove 18A.

A portion of the second-pole second lead 2B overlapping the bulgingportion 25A of the second-pole first lead 2A in the x1-x2-direction issmaller in size in the y-direction than a portion on the x1-directionside. In other words, the portion of the second-pole second lead 2B onthe x2-direction side is recessed upward in the y-direction in FIG. 1.

In this embodiment, the distal end 23B and the groove 28B are located atthe thin portion 21B.

The first-pole third lead 1C is located on the x1-direction side and onthe lower side of the first-pole first lead 1A in the y-direction, asshown in FIG. 1. The first-pole third lead 1C has a strip-like shapeextending in the x1-x2-direction, and includes a thin portion 11C, athick portion 12C, a distal end 13C, a terminal portion 14C, a bulgingportion 15C, and a groove 18C.

The thin portion 11C, having a relatively small thickness compared withthe other portions of the lead 1C, is located on the x2-direction sidein the first-pole third lead 1C. The thick portion 12C, having a greaterthickness than the thin portion 11C, is located on the x1-direction sidein the first-pole third lead 1C. The boundary between the thin portion11C and the thick portion 12C (broken line in FIG. 1) is parallel to they-direction. As shown in FIG. 6, the respective upper faces of the thinportion 11C and the thick portion 12C are flush with each other. Thelower face of the thin portion 11C is covered with the housing 6, andthe lower face of the thick portion 12C is exposed from the housing 6.

The distal end 13C, located at the farthest position on the x2-directionside in the first-pole third lead 1C, is formed as an edge parallel tothe y-direction. The terminal portion 14C is a portion via which the LEDmodule A1 is mounted on a circuit board for example, and provided by theportion of the thick portion 12C exposed from the housing 6.

The bulging portion 15C is located on the x2-direction side, andprotrudes upward in the y-direction in FIG. 1, i.e., toward thefirst-pole first lead 1A.

The groove 18C is formed throughout the first-pole third lead 1C in they-direction. The groove 18C is located on the x1-direction side from thedistal end 13C and the bulging portion 15C. The groove 18C may have across-sectional shape like the one mentioned above with respect to thegroove 18A.

In this embodiment, the distal end 13C, the bulging portion 15C, and thegroove 18C are located at the thin portion 11C.

The second-pole third lead 2C is located on the x2-direction side withrespect to the first-pole third lead 1C and, as shown in FIG. 1, on thelower side of the second-pole first lead 2A in the y-direction. Thesecond-pole third lead 2C has a strip-like shape extending in thex1-x2-direction, and includes a thin portion 21C, a thick portion 22C, adistal end 23C, a terminal portion 24C, and a groove 28C.

The thin portion 21C, having a relatively small thickness compared withthe other portions of the lead 2C, is located on the x1-direction sidein the second-pole third lead 2C. The thick portion 22C, having agreater thickness than the thin portion 21C, is located on thex2-direction side in the second-pole third lead 2C. The boundary betweenthe thin portion 21C and the thick portion 22C (broken line in FIG. 1)is parallel to the y-direction. As shown in FIG. 6, the respective upperfaces of the thin portion 21C and the thick portion 22C are flush witheach other. The lower face of the thin portion 21C is covered with thehousing 6, and the lower face of the thick portion 22C is exposed fromthe housing 6.

The distal end 23C, located at the farthest position on the x1-directionside in the second-pole third lead 2C, is formed as an edge parallel tothe y-direction. The distal end 23C is opposed to the distal end 13C ofthe first-pole third lead 1C in the x1-x2-direction, with a gaptherebetween. The terminal portion 24C is a portion via which the LEDmodule A1 is mounted on a circuit board for example, and provided by theportion of the thick portion 22C exposed from the housing 6.

The groove 28C is formed throughout the second-pole third lead 2C in they-direction. The groove 28C may have a cross-sectional shape like theone mentioned above with respect to the groove 18A.

A portion of the second-pole third lead 2C overlapping the bulgingportion 25A of the second-pole first lead 2A in the x1-x2-direction issmaller in size in the y-direction than a portion on the x1-directionside. In other words, the portion of the second-pole third lead 2C onthe x2-direction side is recessed downward in the y-direction in FIG. 1.

In this embodiment, the distal end 23C and the groove 28C are located atthe thin portion 21C.

The first LED chip 3A is mounted on the thin portion 11A of thefirst-pole first lead 1A, and configured to emit red light in thisembodiment. The first LED chip 3A is a so-called 1-wire LED chip, andhas a non-illustrated upper electrode connected to the second-pole firstlead 2A via the wire 51. A non-illustrated lower electrode of the firstLED chip 3A is joined to the first-pole first lead 1A via anelectroconductive joint material such as an Ag paste or solder. Thefirst LED chip 3A is located between the distal end 13A and the groove18A on the first-pole first lead 1A.

The second LED chip 3B is mounted on the thin portion 21B of thesecond-pole second lead 2B, and configured to emit green light in thisembodiment. The second LED chip 3B is a so-called 2-wire LED chip andincludes a pair of non-illustrated upper electrodes, one of which isconnected to the second-pole second lead 2B via the wire 52 and theother of which is connected to the first-pole second lead 1B via thewire 53. The wire 53 is bonded to the bulging portion 15B of thefirst-pole second lead 1B. In other words, the wire 53 is bonded to thefirst-pole second lead 1B at a position opposite to the second Zenerdiode 4B across the groove 18B. The second LED chip 3B is located on thex2-direction side of the groove 28B, on the second-pole second lead 2B.Further, the second LED chip 3B is located at the same position as thefirst LED chip 3A in the x1-x2-direction.

The third LED chip 3C is mounted on the thin portion 21C of thesecond-pole third lead 2C, and configured to emit blue light in thisembodiment. The third LED chip 3C is a so-called 2-wire LED chip andincludes a pair of non-illustrated upper electrodes, one of which isconnected to the second-pole third lead 2C via the wire 54 and the otherof which is connected to the first-pole third lead 1C via the wire 55.The wire 55 is bonded to the bulging portion 15C of the first-pole thirdlead 1C. In other words, the wire 55 is bonded to the first-pole thirdlead 1C at a position opposite to the third Zener diode 4C across thegroove 18C. The third LED chip 3C is located on the x2-direction side ofthe groove 28C, on the second-pole third lead 2C. Further, the third LEDchip 3C is located at the same position as the first LED chip 3A and thesecond LED chip 3B in the x1-x2-direction.

The first Zener diode 4A is mounted on the first-pole first lead 1A andserves to prevent the first LED chip 3A from being subjected toexcessive reverse voltage. The first Zener diode 4A has anon-illustrated upper electrode connected to the second-pole first lead2A via the wire 56. The wire 56 is bonded to the bulging portion 25A ofthe second-pole first lead 2A. A non-illustrated lower electrode of thefirst Zener diode 4A is joined to the first-pole first lead 1A via anelectroconductive joint material. The first Zener diode 4A is located onthe x1-direction side from the first LED chip 3A, and between the groove18A and the narrowed portion 16A.

The second Zener diode 4B is mounted on the first-pole second lead 1Band serves to prevent the second LED chip 3B from being subjected toexcessive reverse voltage. The second Zener diode 4B has anon-illustrated upper electrode connected to the second-pole second lead2B via the wire 57. The wire is bonded to the second-pole second lead 2Bat a position between the distal end 23B and the groove 28B. Anon-illustrated lower electrode of the second Zener diode 4B is joinedto the first-pole second lead 1B via an electroconductive jointmaterial. The second Zener diode 4B is located on the x1-direction sidefrom the groove 18B.

The third Zener diode 4C is mounted on the first-pole third lead 1C andserves to prevent the third LED chip 3C from being subjected toexcessive reverse voltage. The third Zener diode 4C has anon-illustrated upper electrode connected to the second-pole third lead2C via the wire 58. The wire 58 is bonded to the second-pole third lead2C at a position between the distal end 23C and the groove 28C. Anon-illustrated lower electrode of the third Zener diode 4C is joined tothe first-pole third lead 1C via an electroconductive joint material.The third Zener diode 4C is located on the x1-direction side from thegroove 18C.

As shown in FIG. 1, the distal end 13A of the first-pole first lead 1Ais located on the x2-direction side from the second LED chip 3B and thethird LED chip 3C. In contrast, the distal end 23B of the second-polesecond lead 2B and the distal end 23C of the second-pole third lead 2Care located on the x1-direction side from the first LED chip 3A.

The first Zener diode 4A is located on the x2-direction side from thesecond Zener diode 4B and the third Zener diode 4C. The second Zenerdiode 4B and the third Zener diode 4C are located at the same positionin the x1-x2-direction.

The bulging portion 15B of the first-pole second lead 1B and the bulgingportion 15C of the first-pole third lead 1C are located at the sameposition in the x1-x2-direction. The groove 18B of the first-pole secondlead 1B and the groove 18C of the first-pole third lead 1C are locatedat the same position in the x1-x2-direction. The groove 28B of thesecond-pole second lead 2B and the groove 28C of the second-pole thirdlead 2C are located at the same position in the x1-x2-direction.

The boundary between the thin portion 11A and the thick portion 12A ofthe first-pole first lead 1A, the boundary between the thin portion 11Band the thick portion 12B of the first-pole second lead 1B, and theboundary between the thin portion 11C and the thick portion 12C of thefirst-pole third lead 1C are located at the same position in thex1-x2-direction. Likewise, the boundary between the thin portion 21A andthe thick portion 22A of the second-pole first lead 2A, the boundarybetween the thin portion 21B and the thick portion 22B of thesecond-pole second lead 2B, and the boundary between the thin portion21C and the thick portion 22C of the second-pole third lead 2C arelocated at the same position in the x1-x2-direction.

The housing 6 is formed of a white epoxy resin for example, and has arectangular shape when viewed in the z-direction in this embodiment. Thehousing 6 partially covers each of the first-pole first lead 1A, thesecond-pole first lead 2A, the first-pole second lead 1B, thesecond-pole second lead 2B, the first-pole third lead 1C, and thesecond-pole third lead 2C.

The housing 6 includes a cavity 61. The cavity 61 has a rectangularshape when viewed in the z-direction, and accommodates therein the firstLED chip 3A, the second LED chip 3B, the third LED chip 3C, the firstZener diode 4A, the second Zener diode 4B, and the third Zener diode 4C.

The housing 6 also includes a plurality of linear portions 62. Thelinear portions 62 are formed by fitting a part of the housing 6 in thepair of grooves 18A of the first-pole first lead 1A, the groove 18B ofthe first-pole second lead 1B, the groove 28B of the second-pole secondlead 2B, the groove 18C of the first-pole third lead 1C, and the groove28C of the second-pole third lead 2C. FIG. 4 illustrates the linearportions 62 fitted in the grooves 18A of the first-pole first lead 1A.As shown in FIG. 4, the linear portion 62 slightly protrudes from theupper surface of the first-pole first lead 1A. FIG. 4 also illustratesan electroconductive joint material 31A and an electroconductive jointmaterial 41A. The electroconductive joint material 31A serves to bondthe lower electrode of the first LED chip 3A to the first-pole firstlead 1A. The electroconductive joint material 41A serves to bond thelower electrode of the first Zener diode 4A to the first-pole first lead1A. The linear portions 62 fitted in the groove 18B of the first-polesecond lead 1B, the groove 28B of the second-pole second lead 2B, thegroove 18C of the first-pole third lead 1C, and the groove 28C of thesecond-pole third lead 2C are also configured in the same way as thelinear portions 62 shown in FIG. 4.

The encapsulating resin 7 fills the cavity 61 of the housing 6, so as tocover the first LED chip 3A, the second LED chip 3B, the third LED chip3C, the first Zener diode 4A, the second Zener diode 4B, and the thirdZener diode 4C. The encapsulating resin 7 is formed of, for example, atransparent epoxy resin or silicone resin.

Referring now to FIGS. 7 through 16, an example of the manufacturingmethod of the LED module A1 will be described below.

First, as shown in FIG. 7, a metal plate 10 is prepared. The metal plate10 is the material from which the first-pole first lead 1A, thesecond-pole first lead 2A, the first-pole second lead 1B, thesecond-pole second lead 2B, the first-pole third lead 1C, and thesecond-pole third lead 2C are to be formed. The metal plate 10 may bemade of Cu or Ni or an alloy of these metals. The metal plate 10includes an opening 10 a formed so as to penetrate through the metalplate 10. The metal plate 10 also includes a first-pole first bulgingportion 1A′, a second-pole second bulging portion 2B′, and a second-polethird bulging portion 2C′. The first-pole first bulging portion 1A′ islocated on the x1-direction side with respect to the opening 10 a, andprojects into the opening 10 a toward the x2-direction side. Thesecond-pole second bulging portion 2B′ and the second-pole third bulgingportion 2C′ are located on the respective sides of the first-pole firstbulging portion 1A′ in the y-direction. The second-pole second bulgingportion 2B′ and the second-pole third bulging portion 2C′ are located onthe x2-direction side with respect to the opening 10 a, and project intothe opening 10 a in the x1-direction. In the subsequent steps, the metalplate 10 is to be processed by prescribed stages. The process may bepresswork such as stamping, for example.

Proceeding to FIG. 8, the portion of the metal plate 10 including thesecond-pole second bulging portion 2B′ and the second-pole third bulgingportion 2C′ is stretched in the x1-x2-direction. Accordingly, thesecond-pole second bulging portion 2B′ and the second-pole third bulgingportion 2C′ become longer in the x1-direction. In addition, as shown inFIG. 9, the stretched portion becomes thinner than the remainingportion. However, the upper face in FIG. 9 remains flat, and a steppedportion is formed on the lower face. The shaded area in FIG. 8 and thesubsequent plan views denotes the thin portions formed by the stretchingprocess.

Then, by punching a part of the stretched portion shown in FIG. 8, themetal plate 10 assumes the shape shown in FIG. 10. The punching processchanges the shape of the second-pole second bulging portion 2B′ and thesecond-pole third bulging portion 2C′. In addition, a second-pole firstbulging portion 2A′ is formed between the second-pole second bulgingportion 2B′ and the second-pole third bulging portion 2C′.

By punching a portion of the metal plate 10 on the x2-direction sidewith respect to the second-pole first bulging portion 2A′, thesecond-pole second bulging portion 2B′, and the second-pole thirdbulging portion 2C′, the metal plate 10 assumes the shape shown in FIG.11. As shown in FIG. 11, the second-pole first bulging portion 2A′, thesecond-pole second bulging portion 2B′, and the second-pole thirdbulging portion 2C′ become longer in the x1-x2-direction.

Then the portion of the metal plate 10 including the first-pole firstbulging portion 1A′ is stretched in the x2-direction, as shown in FIG.12. As a result, the first-pole first bulging portion 1A′ is made evenlonger in the x1-x2-direction. In addition, as shown in FIG. 13, thestretched portion becomes thinner than the remaining portion asmentioned above.

Then by punching a part of the portion stretched as shown in FIG. 12,the metal plate 10 assumes the shape shown in FIG. 14. This punchingprocess changes the shape of the first-pole first bulging portion 1A′.At the same time, a first-pole second bulging portion 1B′ and afirst-pole third bulging portion 1C′ are formed on the respective sidesof the first-pole first bulging portion 1A′ in the y-direction.

Further, by punching a portion of the metal plate 10 on the x2-directionside with respect to the first-pole first bulging portion 1A′, thefirst-pole second bulging portion 1B′, and the first-pole third bulgingportion 1C′, the shape shown in FIG. 15 is obtained. As shown in FIG.15, the first-pole first bulging portion 1A′, the first-pole secondbulging portion 1B′, and the first-pole third bulging portion 1C′ aremade longer in the x1-x2-direction.

Further, by punching a part of the regions in the metal plate 10 on therespective sides of the first-pole first bulging portion 1A′, thefirst-pole second bulging portion 1B′, the first-pole third bulgingportion 1C′, the second-pole first bulging portion 2A′, the second-polesecond bulging portion 2B′, and the second-pole third bulging portion2C′ in the y-direction, the shape shown in FIG. 16 is obtained. Throughthe foregoing steps, the portions corresponding to the distal end 13A,the narrowed portion 16A, and the widened portion 17A are formed in thefirst-pole first bulging portion 1A′. Likewise, the portionscorresponding to the distal end 23A and the bulging portion 25A areformed in the second-pole first bulging portion 2A′, and the portionscorresponding to the distal end 13B and the bulging portion 15B areformed in the first-pole second bulging portion 1B′. Further, theportion corresponding to the distal end 23B is formed in the second-polesecond bulging portion 2B′, the portions corresponding to the distal end13C and the bulging portion 15C are formed on the first-pole thirdbulging portion 1C′, and the portion corresponding to the distal end 23Cis formed in the second-pole third bulging portion 2C′.

After completing the foregoing steps, the grooves 18A, the groove 18B,the groove 28B, the groove 18C, and the groove 28C are formed.Alternatively, according to an embodiment of the present invention,those grooves mentioned above may be formed in parallel with orsimultaneously with the foregoing steps.

Thereafter, the first LED chip 3A is mounted on the first-pole firstbulging portion 1A′, the second LED chip 3B is mounted on thesecond-pole second bulging portion 2B′, and the third LED chip 3C ismounted on the second-pole third bulging portion 2C′. In addition, thefirst Zener diode 4A is mounted on the first-pole first bulging portion1A′, the second Zener diode 4B is mounted on the first-pole secondbulging portion 1B′, and the third Zener diode 4C is mounted on thefirst-pole third bulging portion 1C′. Then the wires 51 to 58 are bondedin a prescribed manner. After the mentioned mounting and bondingprocess, the housing 6 is formed. Alternatively, the housing 6 may beformed before the mounting and bonding process. Then the encapsulatingresin 7 is formed. Then upon cutting away predetermined positions of themetal plate 10, the LED module A1 shown in FIG. 1 is obtained.

The foregoing LED module A1 and the manufacturing method thereof providethe following advantageous effects.

With the configuration according to the present embodiment, the distalend 13A of the first-pole first lead 1A is located on the x2-directionside (i.e., offset in the x2-direction) with respect to the distal end23B of the second-pole second lead 2B and the distal end 23C of thesecond-pole third lead 2C. Accordingly, the first LED chip 3A (mountedon the first-pole first lead 1A) can be brought closer to the second LEDchip 3B (mounted on the second-pole second lead 2B) and to the third LEDchip 3C (mounted on the second-pole third lead 2C). Thus, the LED moduleA1 can be formed in a smaller size.

Further, the distal end 13A of the first-pole first lead 1A is locatedon the x2-direction side with respect to the second LED chip 3B and thethird LED chip 3C, which is advantageous to bringing the first LED chip3A closer to the second LED chip 3B and to the third LED chip 3C.

Still further, the distal end 23B of the second-pole second lead 2B andthe distal end 23C of the second-pole third lead 2C are located on thex1-direction side with respect to the first LED chip 3A, which isadvantageous to bringing the first LED chip 3A closer to the second LEDchip 3B and to the third LED chip 3C.

The first LED chip 3A, the second LED chip 3B, and the third LED chip 3Care disposed so as to at least partially overlap in the x1-x2-direction(in other words, at least partially overlap as viewed in they-direction), and the centers of the respective chips 3A, 3B and 3C arelocated at the same position in the x1-x2-direction. This configurationis advantageous to arranging the first LED chip 3A, the second LED chip3B, and the third LED chip 3C close to each other.

The distal end 23B of the second-pole second lead 2B and the distal end23C of the second-pole third lead 2C are located at the same position inthe x1-x2-direction, which is advantageous to arranging the second LEDchip 3B and the third LED chip 3C properly with respect to the first LEDchip 3A.

The wire 56 is bonded to the bulging portion 25A of the second-polefirst lead 2A, which is advantageous to preventing the wire 56 and thewire 51 from interfering with each other.

The second-pole second lead 2B and the second-pole third lead 2C have aportion that overlaps the bulging portion 25A of the second-pole firstlead 2A in the x1-x2-direction, and each of these portions of the leads2B, 2C is smaller in size measured in the y-direction than the portionsof the leads 2B, 2C upon which the second LED chip 3B and the third LEDchip 3C are mounted. This configuration is advantageous to preventingthe capillary for bonding the wires from interfering with an unexpectedpart.

The wire 53 is bonded to the bulging portion 15B of the first-polesecond lead 1B, which is advantageous to preventing the wire 53 and thewire 57 from interfering with each other. Likewise, the wire 55 isbonded to the bulging portion 15C of the first-pole third lead 1C, whichis advantageous to preventing the wire 55 and the wire 58. frominterfering with each other.

The first-pole first lead 1A includes the narrowed portion 16A and thewidened portion 17A, which is advantageous to preventing the first-polefirst lead 1A from coming off from the housing 6.

The two linear portions 62 of the housing 6 are respectively fitted inthe two grooves 18A of the first-pole first lead 1A, so that thefirst-pole first lead 1A is stably held by the linear portions 62. Thisconfiguration prevents the first-pole first lead 1A from coming off fromthe housing 6.

The grooves 18A are located between the first LED chip 3A and the firstZener diode 4A, which is advantageous to preventing theelectroconductive joint material 31A and the electroconductive jointmaterial 41A (see FIG. 4) from spreading unduly.

On the first-pole second lead 1B, the linear portion 62 of the housing 6fitted in the groove 18B serves to prevent the electroconductive jointmaterial for fixing the Zener diode 4B from spreading to the regionwhere the wire 53 is to be bonded. Likewise, on the second-pole secondlead 2B the linear portion 62 of the housing 6 fitted in the groove 28Bserves to prevent the joint material for fixing the second LED chip 3Bfrom spreading to the region where the wire 57 is to be bonded.

On the first-pole third lead 1C, the linear portion 62 of the housing 6fitted in the groove 18C serves to prevent the electroconductive jointmaterial for fixing the Zener diode 4C from spreading to the regionwhere the wire 55 is to be bonded. Likewise, on the second-pole thirdlead 2C the linear portion 62 of the housing 6 fitted in the groove 28Cserves to prevent the joint material for fixing the third LED chip 3Cfrom spreading to the region where the wire 58 is to be bonded.

The first-pole first lead 1A, the second-pole first lead 2A, thefirst-pole second lead 1B, the second-pole second lead 2B, thefirst-pole third lead 1C, and the second-pole third lead 2C include thethin portion 11A, the thin portion 21A, the thin portion 11B, the thinportion 21B, the thin portion 11C, and the thin portion 21C,respectively. This configuration prevents the six leads 1A, 2A, 1B, 2B,1C and 2C from coming off from the housing 6.

By stretching the metal plate 10 with the first-pole first bulgingportion 1A′, the second-pole second bulging portion 2B′, and thesecond-pole third bulging portion 2C′, the portions corresponding to thefirst-pole first lead 1A, the second-pole first lead 2A, the first-polesecond lead 1B, the second-pole second lead 2B, the first-pole thirdlead 1C, and the second-pole third lead 2C are sequentially formed.Through such steps, it is possible to easily and accurately form thefirst-pole first lead 1A, the second-pole first lead 2A, the first-polesecond lead 1B, the second-pole second lead 2B, the first-pole thirdlead 1C, and the second-pole third lead 2C, respectively including thedistal end 13A, the distal end 23A, the distal end 13B, the distal end23B, the distal end 13C, and the distal end 23C that are shifted fromeach other in the x1-x2-direction.

FIG. 17 illustrates an LED module according to a second embodiment ofthe present invention. In FIG. 17, the elements and members that are thesame as or similar to those of the first embodiment are given the samereference numeral.

In the LED module A2 according to this embodiment, the first-pole firstlead 1A includes a pair of lateral projections or lugs 19A. Similarly,the second-pole first lead 2A includes a pair of lateral lugs 29A, thefirst-pole second lead 1B includes a pair of lateral lugs 19B, thesecond-pole second lead 2B includes a pair of lateral lugs 29B, thefirst-pole third lead 1C includes a pair of lateral lugs 19C, and thesecond-pole third lead 2C includes a pair of lateral lugs 29C.

The lateral lugs 19A extend oppositely from the thick portion 12A of thefirst-pole first lead 1A in the y-direction, and the lateral lugs 29Aextend oppositely from the thick portion 22A of the second-pole firstlead 2A in the y-direction. The lateral lugs 19B extend oppositely fromthe thick portion 12B of the first-pole second lead 1B in they-direction, and the lateral lugs 29B extend oppositely from the thickportion 22B of the second-pole second lead 2B in the y-direction. Thelateral lugs 19C extend oppositely from the thick portion 12C of thefirst-pole third lead 1C in the y-direction, and the lateral lugs 29Cextend oppositely from the thick portion 22C of the second-pole thirdlead 2C in the y-direction.

The lateral lugs 19A, 29A, 19B, 29B, 19C and 29C are covered with thehousing 6. The lateral lugs 19A, 29A, 19B, 29B, 19C and 29C may be thesame in thickness as the thick portion 12A, 22A, 12B, 22B, 12C and 22C,respectively, or the same in thickness as the thin portion 11A, 21A,11B, 21B, 11C and 21C, respectively.

The LED module A2 according to the second embodiment can also be formedin a small size. In addition, forming the pairs of lateral lugs 19A,29A, 19B, 29B, 19C and 29C effectively prevents the leads 1A, 2A, 1B,2B, lead 1C and 2C from coming off from the housing 6.

The LED module and the manufacturing method according to the presentinvention are not limited to the foregoing embodiments. Theconfiguration of the LED module and the steps of the manufacturingmethod may be modified in various manners within the scope of thepresent invention.

The invention claimed is:
 1. An LED module comprising: a first-polefirst lead, a first-pole second lead, and a first-pole third leadlocated on a first-pole side in a first direction; a second-pole firstlead, a second-pole second lead, and a second-pole third lead located ona second-pole side opposite the first-pole side in the first direction;a first LED chip electrically connected to the first-pole first lead andthe second-pole first lead; a second LED chip electrically connected tothe first-pole second lead and the second-pole second lead; a third LEDchip electrically connected to the first-pole third lead and thesecond-pole third lead; a housing covering at least a part of each ofthe first-pole first lead, the first-pole second lead, the first-polethird lead, the second-pole first lead, the second-pole second lead andthe second-pole third lead; wherein a distal end of the first-pole firstlead and a distal end of the second-pole first lead are opposed to eachother in the first direction, a distal end of the first-pole second leadand a distal end of the second-pole second lead are opposed to eachother in the first direction, a distal end of the first-pole third leadand a distal end of the second-pole third lead are opposed to each otherin the first direction, the first-pole first lead is located between thefirst-pole second lead and the first-pole third lead in a seconddirection orthogonal to the first direction, and the second-pole firstlead is located between the second-pole second lead and the second-polethird lead in the second direction, the first LED chip is mounted on thefirst-pole first lead, the second LED chip is mounted on the second-polesecond lead, and the third LED chip is mounted on the second-pole thirdlead, and the distal end of the first-pole first lead is offset towardthe second-pole side in the first direction with respect to the distalend of the second-pole second lead and the distal end of the second-polethird lead; wherein the first LED chip, the second LED chip and thethird LED chip having portions at least partially overlapping in thefirst direction.
 2. The LED module according to claim 1, wherein thedistal end of the first-pole first lead is offset toward the second-poleside in the first direction with respect to the second LED chip and thethird LED chip.
 3. The LED module according to claim 2, wherein thedistal end of the second-pole second lead and the distal end of thesecond-pole third lead are offset toward the second-pole side in thefirst direction with respect to the first LED chip.
 4. The LED moduleaccording to claim 3, wherein the distal end of the second-pole secondlead and the distal end of the second-pole third lead are located at asame position in the first direction.
 5. The LED module according toclaim 1, wherein the first LED chip, the second LED chip and the thirdLED chip have centers located at a same position in the first direction.6. The LED module according to claim 1, wherein the first LED chip iselectrically connected to the first-pole first lead and connected to thesecond-pole first lead via a wire.
 7. The LED module according to claim6, wherein the second LED chip is connected to each of the first-polesecond lead and the second-pole second lead via a wire, and the thirdLED chip is connected to each of the first-pole third lead and thesecond-pole third lead via a wire.
 8. The LED module according to claim7, further comprising: a first Zener diode mounted on the first-polefirst lead to prevent the first LED chip from being subjected to reversevoltage; a second Zener diode mounted on the first-pole second lead toprevent the second LED chip from being subjected to reverse voltage; anda third Zener diode mounted on the first-pole third lead to prevent thethird LED chip from being subjected to reverse voltage.
 9. The LEDmodule according to claim 8, wherein the first Zener diode is offsettoward the first-pole side in the first direction with respect to thefirst LED chip.
 10. The LED module according to claim 9, wherein thefirst Zener diode is offset toward the second-pole side in the firstdirection with respect to the second Zener diode and the third Zenerdiode.
 11. The LED module according to claim 10, wherein the secondZener diode and the third Zener diode are located at a same position inthe first direction.
 12. The LED module according to claim 8, whereinthe second-pole first lead includes a bulging portion projecting in thesecond direction, and the bulging portion is connected to the firstZener diode via a wire.
 13. The LED module according to claim 12,wherein a portion of the second-pole second lead that overlaps thebulging portion of the second-pole first lead in the first direction issmaller in size measured in the second direction than another portion ofthe second-pole second lead that supports the second LED chip, and aportion of the second-pole third lead that overlaps the bulging portionof the second-pole first lead in the first direction is smaller in sizemeasured in the second direction than another portion of the second-polethird lead that supports the third LED chip.
 14. The LED moduleaccording to claim 12, wherein the first-pole second lead includes abulging portion projecting in the second direction toward the first-polefirst lead, and the first-pole third lead includes a bulging portionprojecting in the second direction toward the first-pole first lead, thebulging portion of the first-pole second lead is connected to the secondLED chip via the wire, and the bulging portion of the first-pole thirdlead is connected to the third LED chip via the wire.
 15. The LED moduleaccording to claim 14, wherein the bulging portion of the first-polesecond lead and the bulging portion of the first-pole third lead aredisposed to overlap the first Zener diode in the first direction. 16.The LED module according to claim 12, wherein the first-pole first leadincludes a narrowed portion that is offset toward the first-pole side inthe first direction with respect to the first Zener diode, the narrowedportion having a relatively small size measured in the second direction.17. The LED module according to claim 16, wherein the first-pole firstlead includes a widened portion that is offset toward the first-poleside in the first direction with respect to the narrowed portion, thewidened portion having a relatively great size measured in the seconddirection.
 18. The LED module according to claim 8, wherein a surface ofthe first-pole first lead on which the first LED chip is mounted isformed with a groove extending in the second direction, said groovebeing filled with a part of the housing.
 19. The LED module according toclaim 18, wherein the surface of the first-pole first lead on which thefirst LED chip is mounted is formed with an additional groove extendingin the second direction, and wherein said groove and the additionalgroove are disposed between the first LED chip and the first Zener diodein the first direction.
 20. The LED module according to claim 18,wherein a surface of the second-pole second lead on which the second LEDchip is mounted is formed with a groove extending in the seconddirection and filled with a part of the housing, and wherein a surfaceof the second-pole third lead on which the third LED chip is mounted isformed with a groove extending in the second direction and filled with apart of the housing.
 21. The LED module according to claim 20, whereinthe groove of the second-pole second lead is offset toward thefirst-pole side in the first direction with respect to the second LEDchip, and the groove of the second-pole third lead is offset toward thefirst-pole side in the first direction with respect to the third LEDchip.
 22. The LED module according to claim 20, wherein a surface of thefirst-pole second lead on which the second Zener diode is mounted isformed with a groove extending in the second direction and filled with apart of the housing, and wherein a surface of the first-pole third leadon which the third Zener diode is mounted is formed with a grooveextending in the second direction and filled with a part of the housing.23. The LED module according to claim 22, wherein the groove of thefirst-pole second lead is offset toward the second-pole side in thefirst direction with respect to the second Zener diode, and the grooveof the first-pole third lead is offset toward the second-pole side inthe first direction with respect to the third Zener diode.
 24. The LEDmodule according to claim 8, wherein each of the first-pole first lead,the second-pole first lead, the first-pole second lead, the second-polesecond lead, the first-pole third lead and the second-pole third leadincludes a thin portion and a thick portion that is greater in thicknessthan the thin portion, and each of the thin portion and the thickportion includes an obverse surface and a reverse surface, the obversesurface of the thin portion being flush with the obverse surface of thethick portion, the reverse surface of the thick portion being exposedfrom the housing, and wherein the first LED chip, the second LED chipand the third LED chip are mounted on the thin portion of the first-polefirst lead, the thin portion of the second-pole second lead, and thethin portion of the second-pole third lead, respectively.
 25. The LEDmodule according to claim 24, wherein a boundary between the thinportion and the thick portion of the first-pole first lead, a boundarybetween the thin portion and the thick portion of the first-pole secondlead, and a boundary between the thin portion and the thick portion ofthe first-pole third lead are located at a same position in the firstdirection, and wherein a boundary between the thin portion and the thickportion of the second-pole first lead, a boundary between the thinportion and the thick portion of the second-pole second lead, and aboundary between the thin portion and the thick portion of thesecond-pole third lead are located at a same position in the firstdirection.
 26. The LED module according to claim 1, wherein the firstLED chip is configured to emit red light, one of the second LED chip andthe third LED chip is configured to emit blue light, and the other ofthe second LED chip and the third LED chip is configured to emit greenlight.